Hierarchical shrinkage in time-varying parameter models

In this paper, we forecast EU-area inflation with many predictors using time-varying parameter models. The facts that time-varying parameter models are parameter-rich and the time span of our data is relatively short motivate a desire for shrinkage. In constant coefficient regression models, the Bayesian Lasso is gaining increasing popularity as an effective tool for achieving such shrinkage. In this paper, we develop econometric methods for using the Bayesian Lasso with time-varying parameter models. Our approach allows for the coefficient on each predictor to be: i) time varying, ii) constant over time or iii) shrunk to zero. The econometric methodology decides automatically which category each coefficient belongs in. Our empirical results indicate the benefits of such an approach

Transient evoked otoacoustic emissions testing for screening of sensorineural deafness in puppies

<p><b>Background:</b> Transient evoked otoacoustic emissions (TEOAE) are widely used for human neonatal deafness screening, but have not been reported for clinical use in dogs.</p> <p><b>Hypothesis/Objectives:</b> To investigate the feasibility of TEOAE testing in conscious puppies and the ability of TEOAE testing to correctly identify deaf and hearing ears, as defined by brainstem auditory evoked response (BAER).</p> <p><b>Animals:</b> Forty puppies from 10 litters.</p> <p><b>Methods:</b> Prospective study on puppies presented for hearing assessment as part of a congenital deafness BAER screening program. Hearing status was determined using BAER. TEOAE testing was performed after the BAER assessment and the results of the TEOAE testing were compared with the hearing status for each ear. Parameters were tested for normality using the D'Agostino Pearson test and comparisons between the deaf and hearing ears were made using Mann-Whitney tests.</p> <p><b>Results:</b> TEOAE testing was readily performed in puppies presented for congenital deafness screening. Using analysis parameters based on those used in human neonatal hearing screening, TEOAE testing correctly identified all deaf ears, as defined by BAER testing, with a sensitivity of 100% (95% CI: 56-100%) for diagnosing deafness and specificity of 78% (95% CI: 66-87%).</p> <p><b>Conclusions and Clinical Importance:</b> TEOAE testing is an effective screening modality for identifying congenital sensorineural deafness in dogs. In light of the simpler and less expensive equipment, TEOAE testing has the potential to improve access to hearing screening and through this reduce the prevalence of congenital deafness in the dog.</p&gt

Blazing the Trail: A Qualitative Case Study of Mentoring in a Gender Equity Leadership Development Program

This instrumental qualitative case study examines a formal mentoring program in fulfillment of a National Science Foundation (NSF) ADVANCE grant at SouthEast University. A total of 38 executive mentors and 58 protégées participated in a program that promoted gender equity leadership, professional development, and advancement. The purpose of this study was to explore mentor and mentee perceptions of learning and development experiences, and to determine the efficacy of program elements and leadership pipeline access for women faculty. Based on the results, we offer suggestions for improvement and lessons learned that can help inform similar combined mentoring and leadership development initiatives

Evaluation of some important physicochemical properties of starch free grewia gum

Gums obtained by extraction from the inner bark of stems can be found in association with starch, which must be digested in order to obtain a refined polysaccharide isolate. In the present study, grewia gum obtained from the inner bark of the stems of Grewia mollis was shown to co-exist with starch and the effect of starch digestion on the physicochemical properties of the resultant polysaccharide was evaluated. The gum was extracted by maceration of the inner bark in deionized water and isolated by a combination of filtration, centrifugation and finally precipitation with absolute ethanol to produce the crude grewia gum extract (GG). The presence and content of starch in the gum sample was determined followed by enzymatic digestion of the starch using α-amylase (Termamyl 120L) to give a starch-free extract (GGDS). Physicochemical properties of the extracts such as total carbohydrates, total protein, differential sugar composition, NMR, intrinsic viscosity and rheological behaviour of the samples were evaluated. The GG extract had total carbohydrate content of ∼ 60 % out of which 11.8 % was starch, and a protein content of 2.3 %. Samples also contained galacturonic and glucuronic acid which were highly acetylated. Both samples had a higher proportion of galacturonic acid than glucuronic acid and contained rhamnose, arabinose, galactose, glucose and xylose as neutral sugars in varying proportions. Rheological measurements on 2 %w/w dispersions of the extracts show minor differences between both the original extract and the de-starched material but were influenced by changes in pH

A General Bayesian Framework to Account for Foreground Map Errors in Global 21-cm Experiments

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a physics-motivated parametric forward model of the data within a Bayesian framework provides a robust means to separate the signal from the foregrounds, given sufficient information about the instrument and sky. It has previously been demonstrated that, within such a modelling framework, a foreground model of sufficient fidelity can be generated by dividing the sky into $N$ regions and scaling a base map assuming a distinct uniform spectral index in each region. Using the Radio Experiment for the Analysis of Cosmic Hydrogen (REACH) as our fiducial instrument, we show that, if unaccounted-for, amplitude errors in low-frequency radio maps used for our base map model will prevent recovery of the 21-cm signal within this framework, and that the level of bias in the recovered 21-cm signal is proportional to the amplitude and the correlation length of the base-map errors in the region. We introduce an updated foreground model that is capable of accounting for these measurement errors by fitting for a monopole offset and a set of spatially-dependent scale factors describing the ratio of the true and model sky temperatures, with the size of the set determined by Bayesian evidence-based model comparison. We show that our model is flexible enough to account for multiple foreground error scenarios allowing the 21-cm sky-averaged signal to be detected without bias from simulated observations with a smooth conical log spiral antenna.Comment: 18 pages, 13 figure

Metabolically exaggerated cardiac reactions to acute psychological stress revisited

The reactivity hypothesis postulates that large magnitude cardiovascular reactions to psychological stress contribute to the development of pathology. A key but little tested assumption is that such reactions are metabolically exaggerated. Cardiac activity, using Doppler echocardiography, and oxygen consumption, using mass spectrometry, were measured at rest and during and after a mental stress task and during graded submaximal cycling exercise. Cardiac activity and oxygen consumption showed the expected orderly association during exercise. However, during stress, large increases in cardiac activity were observed in the context of modest rises in energy expenditure; observed cardiac activity during stress substantially exceeded that predicted on the basis of contemporary levels of oxygen consumption. Thus, psychological stress can provoke increases in cardiac activity difficult to account for in terms of the metabolic demands of the stress tas

Animal spirits and credit cycles

In this paper we extend the behavioral macroeconomic model as proposed by De Grauwe (2012) to include a banking sector. The behavioral model takes the view that agents have limited cognitive abilities. As a result, it is “rational” to use simple forecasting rules and to subject the use of these rules to a fitness test. Agents are then driven to select the rule that performs best. The behavioral model produces endogenous and self-fulfilling movements of optimism and pessimism (animal spirits). Our main result is that the existence of banks intensifies these movements, creating a greater scope for booms and busts. Thus, banks do not create but amplify animal spirits. We find that increases in the equity ratios of banks tend to reduce the importance of animal spirits over the business cycle. The other policy conclusion we derive from our results is that the central bank has an important responsibility for stabilising output: output stabilization is an instrument to “tame the animal spirits”. This has the effect of improving the trade-off between inflation and output volatility